Ground-detector.



No. 730,595. 'PATENTED JUNE 9, 1903. 0.0; BADEAU.

GROUND DETEGTOR. APPLIOATION FILED JULY 26,1901. I

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Inventor Charles Cfiadeau.

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Witnesses.

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UNITED I STATES Patented June 9, 1903.

PATENT OFFICE.

CHARLES C. BADEAU, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

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SPECIFICATION forming part of Letters Patent No. 730,595, dated June 9, 1903.

Application filed July 26, 1901.

To aZZ whom it may concern:

Be it known that I, CHARLES C. BADEAU, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Ground-Detectors, (Case No. 2,215,) of which the following is a specification.

The object of this invention is to provide an efiective ground-detector for electric circuits and to distinguish between a static and dynamic discharge by a device durable and simple in construction.

The essential feature of my invention consists in providing a spark-gap between the lines and earth at the point at which the detector is located and means for increasing the length of said gap with respect to a charge between the line-wires.

The best form I have thus far devised in carrying out the invention comprisesfla plurality of gaps with respect to the line-wires, the aggregate sparking distance of which the potential of the line isunable to bridge, and a switch for throwing on and ofi a ground. Thus if a discharge occurs across the gaps a removal of the ground will force the potential to traverse the aggregate arcing distance, and since the line-potential is unable to do this a dynamic discharge will be quieted, thereby indicating the character of the discharge; I include in series with .the device a resistance for cutting down the current, so as to prevent destruction of the contacts.

My invention therefore consists in a grounddetector provided with means for requiring a longer path of discharge from wire to wire than from any wire to ground in connection with a switch for throwing oh? and on the ground and comprises also a plurality of dis charge-paths from difiereut line-wires in connection with a common ground-switch.

The novel features will be more particularly hereinafter described and will be definitely indicated'in the claims appended to this specification.

In the accompanying drawings, which illustrate the invention, Figure 1 is a front View of an apparatus embodying my improve- 50 inents. Fig. 2 is a side elevation, and Fig. 3

Serialll'o. 69,742. on model.)

is a diagram showing the relation of the instrument to a circuit.

Referring first to Figs. 1 and 2, 1 2 3 represent terminals adapted to be connected with I leads from a circuit. The device shown is adapted to three-wire circuits or triphase' circuits, though my improvements are in no respect limited to such an application. In series with the terminals are resistance-blocks 4 5 6, such as a baked mixture of graphite and clay, connected in series relation to sparkgaps 7 8 9, mounted in a common metal support 10, adapted for connection with ground through a switch 11. Each gap may be varied in length by means of adjusting-screws 12 1314. The parts are supported upon insulatingpillars, as 15, mounted upon a base 16. In a three-wire circuit the terminals 1 2 3 are connected with the three line-wires, respectively, or for a two-wire circuit two may be so connected. The gaps are adj usted with respect to the circuit so that the arcing distance of the several gaps interposed between the line-wires will be longer than thepotential of the system can jump. The switch is normally closed. Thus if a. ground occurs on the system the line-potential is SllffiGlOllli to spark across but one of the gaps,and byopenin g the switch the sparking will cease. If, however, the discharge is a static one, the sparking will still continue, since the aggregate gap is within jumping distance of' a static discharge.

The dotted line 17 in Fig. 3 indicates a supposed ground on one of the line-wires. The switch 11 being assumed closed, the gap will be bridged; but opening the switch will quiet the discharge if dynamic in character.

If, however, the discharge is static, it will still continue. for each wire, since an indication thus is atforded as to the wire on which the ground occurs. The parts being in multiple, the grounded wire will be the only one in, whose spark-gapno sparking will occur.' The in- 5 terposition of the resistance-blocks 4: 5 6 cuts down the current, thus preventing damage to the instrument and waste of energy and at the same time acts as a relief for the line from static charges.

I preferably provide a gap 0 Having thus described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. A ground-detector having a spark-gap of greater dielectric resistance between the line-terminals than to ground, and means for cutting on and off the ground.

2. A ground-detector provided with arcingterminals having a longer gap in series with the line-wires than to ground, and means for opening and closing the ground.

3. A ground-detector provided with a plurality of spark-gaps in parallel relation to the several line-wires and ground, and means for throwing on and off the ground.

4. A ground-detector provided with a plurality of spark-gaps between ground and the several line-wires, and means for throwing hand this 24th day of July, 1901.

CHARLES C. BADEAU. Witnesses:

BENJAMIN B. HULL, FRED Ross. 

